There is a scandal behind the latest release of emails written by climate scientists but is not about climate science. The true scandal is how, two years on, no one still has a clue who obtained the emails and why they so carefully timed their release for just before the UN's annual climate change negotiations.

It matters. Those negotations are central to the world's efforts to tackling global warming and while, even in Copenhagen in 2009, the emails were barely discussed by governments, they have diverted debate from the real issues and spread confusion.

The police inquiry, led by Norfolk Constabulary, has spent nothing on the investigation since March this year, and only £6,000 in the six months before that, according to Freedom of Information responses. That is not good enough.

Until we know the identity and motivation of those behind the release of the emails, they still present a danger. That is because, while the scientific case for urgent action to preserve the Earth's climate stability is being made, political will is weak. And if doubt is cast in the minds of voters, politicians do not feel the pressure to act.

The release of the emails is a classic "merchants of doubt" tactic, stolen from the tobacco industry who realised that when the scientific case was unanswerable, casting uncertainty on it was a very effective way to block action.

For the avoidance of doubt: the case for action on global warming is built on many different lines of evidence from the melting Arctic to sophisticated modelling of future climate. Even just considering the most recent evidence, the case is compelling.

The study from the Berkeley, designed as a sceptical, independent look at temperature records, entirely replicated existing records. The International Energy Agency, a conservative body with a fossil fuel heritage, stated starkly in its recent report that we face locking in dangerous warming within a few years. And in Durban from Monday, the world's nations will join once again completely unanimous in their agreement that we are causing climate change and that we must act to stop it.

Today, Phil Jones, the scientist at the centre of the email chains, said he would not be judged on not his emails but on his scientific papers. The nations of the world meeting at the UN are attempting to do just that: judge the action required on the ample evidence available. But until the merchants of doubt who seek to poison the debate are unmasked, that already Herculean task will be even harder.